The Cure for blown/cut patches! Maybe

[Roger Fisher]

This is a follow up to the thread called 'fliers due to cut/blown patches posted a couple or three days ago.  The top row are patches I picked up after getting fliers at 50 yds offhand that I couldn't call.  This was a mild charge of 62 gr 3 f  .454 ball Goex .016/.017 patches spit.  There were also many patches in good shape....

Monday I shot 16 or 17 shots with only one change and that was using an 80 gr charge instead of 62.  All of the patches I found were in good shape (with the pressured lands showing on the patches..)  So Murphy and his law dictated that the very last patch I found had two land cuts (the lower right patch)  This test was after I had worked a 4/0 wad on jag on steel rod very tightly thru the old girl about 15 trips end to end with extra attention to the fouling ring area in the breech and of course the muzzle.   Bottom line is that (apparently) there was a rough spot on 2 or so lands that I couldn't see nor feel and the job with the 4/0 smoothed her out to a near excellent condition...  I have since followed with the same treatment again and more testing will be done to see if I can find any more cut patches... This is a coal black twill type of patching from good ol Wade Reynolds of Carolina Calicos.. This barrel has well over (well over) 60,000 rounds thru her and was well taken care of.
My judgement tells me that the muzzle was the culprit.

Result is that it seemed the cure worked (generally)

[Daryl]

Black or very dark grey cotton?

This combination might not work well in warm weather.  Are the patches laid out in order, bottom to top?  I not the first one, far right on the bottom is also cut - was it the first or should it be in the second row form the top, the last 6 shots fired?  Most patches shoing the land side, show highly stressed cloth.

Rough bore will cause this, as will a slightly sharp crown, as will too-thin a patch- when shooting underized balls(smaller than bore size)

[bs2]

Roger Fisher,

New bore, old bore, we need more info.

I have one that is simular, one grove has some chatter,[deep cut] about a 1/2-3/4" long, this will let the gases cut a hole in the patch, as they try to go around the side, but only on the first clean bore shot. I lapped the bore with a long lead 'slug', it helped.

My solution is a heavy canvas patch and tight fitting ball on the first shot. Second and third shot can be ticking, guess that chatter fills with 'crud' and....................

No-BS

[Larry Pletcher]

Roger,
I heard a new (to me) theory about blown patches that could have a bearing on your example.  A bench shooter at friendship told me that if a bench  gun is burning patches they increase the charge until it quits.  The idea is that in a longer powder column, the powder immediately behind the ball isn't burnt until the ball has already begun moving and pressures are beginning to decrease.  The forward part of the powder column acts like a cushion for the ball while the back part of the column is burning.

This is new to me but I will be trying it out on a .54 Rice barrel.  A 65 gr charge burns patches at times. I thought it might have been a difference in the amount of lube on the patch.  A spit patch doesn't burn.  I will see what happens with an increased charge.

Regards,
Pletch

[Dphariss]

Sometimes its just a specific batch of patching. I had a rash of this with the 54 DK Hawken some years back maybe one in a session of shooting.
Has not done it since and I changed nothing but simply used up the patch material.

I have thought that the long powder column acted as a wad.

Dan

[Roger Fisher]

Roger,
I heard a new (to me) theory about blown patches that could have a bearing on your example.  A bench shooter at friendship told me that if a bench  gun is burning patches they increase the charge until it quits.  The idea is that in a longer powder column, the powder immediately behind the ball isn't burnt until the ball has already begun moving and pressures are beginning to decrease.  The forward part of the powder column acts like a cushion for the ball while the back part of the column is burning.

This is new to me but I will be trying it out on a .54 Rice barrel.  A 65 gr charge burns patches at times. I thought it might have been a difference in the amount of lube on the patch.  A spit patch doesn't burn.  I will see what happens with an increased charge.

Regards,
Pletch

Now thats interesting and let us know what your result is!   BTW we all thank you for your excellent photo work!

[Roger Fisher]

Update, fired 16 shots today using same combos except used 75 3f Goex in lieu of 80!   Found all of the patches all in fine shape.  This was after another session with 4/0 on the jag and steel rod tight fit.  I'm feeling happier than a hog in slop.  Hope it lasts.!

[Daryl]

Sounds encouraging, Roger.  I find a load that is 'on the edge' as to patch integrity, will fail with an increase of 10F or 15F ambient temperature.

[Larry Pletcher]

Today I tried a few things to see if an increased charge lessened the damage to the patch.  My previous charge was 65 gr Swiss fffg.  I changed to 75 gr ffg swiss.  The remaining load was not changed:
.530 ball
.019 pocket drill
bees wax/olive oil lube
loaded from bullet block
no wiping between shots

The first shot burned the patch (clean barrel).  The next 17 shots did NOT burn patches.  At this point the group made me wonder if wiping the barrel would change the group. so I wiped the barrel and fired the next shot - and burned the patch (clean barrel).  The last of this series was fired without wiping and did NOT burn the patch.   Did the fouling that accumulated in the grooves protect the patch?  Looked like it with this load.

Next I changed the ball and patch lube. This load now was:
75 gr Swiss ffg
.535 ball
.019 pocket drill
spit for lube
seated at muzzle instead of a block
no wiping between shots

This group left patches that could be reused.  I didn't because I had a good 25 yd group going.  The 5 shots' centers could easily be covered with a dime.  This will be my group.  

I shot this with a WL liner as Jim sends it - .055".  I had to pay more attention to
it than I'm used to doing.  I like a bigger vent, but will increase it gradually.
Regards,
Pletch

[Roger Fisher]

Today I tried a few things to see if an increased charge lessened the damage to the patch.  My previous charge was 65 gr Swiss fffg.  I changed to 75 gr ffg swiss.  The remaining load was not changed:
.530 ball
.019 pocket drill
bees wax/olive oil lube
loaded from bullet block
no wiping between shots

The first shot burned the patch (clean barrel).  The next 17 shots did NOT burn patches.  At this point the group made me wonder if wiping the barrel would change the group. so I wiped the barrel and fired the next shot - and burned the patch (clean barrel).  The last of this series was fired without wiping and did NOT burn the patch.   Did the fouling that accumulated in the grooves protect the patch?  Looked like it with this load.

Next I changed the ball and patch lube. This load now was:
75 gr Swiss ffg
.535 ball
.019 pocket drill
spit for lube
seated at muzzle instead of a block
no wiping between shots

This group left patches that could be reused.  I didn't because I had a good 25 yd group going.  The 5 shots' centers could easily be covered with a dime.  This will be my group.  

I shot this with a WL liner as Jim sends it - .055".  I had to pay more attention to
it than I'm used to doing.  I like a bigger vent, but will increase it gradually.
Regards,
Pletch

Well now Larry thats why I load 'em tight..!  .454 ball 015/016 spit patch no seperate wiping 'tween shots. 62 Goex 3 F @ 50 yds.  80 3 F goex at 100!

[Daryl]

I am of the opinion that Lyman had it right, when they printed their first BP manual - this is, when seated into the bore than removed, the ball should show rifling marks, not only form the lands but from the grooves.  Whenever I try to skimp on patch thickness, I get cut and blown patches. When I load a thick enough patch to give both land and groove impressions on a pure lead ball, the patches are not only re-usable, but I've done that many times, re-use them, that is, and accuracy is not diminished and even after firing the second time, they are actually reuseable the second and more times as well.

I once shot a 5-shot offhand group at 50 yards with the 14 bore to prove a point to a fellow who was 'resisting' learning about patch integrity.  I had him watch the patch fall each shot and retrieve it for me. I re-lubed that patch and used the same patch for each of the 5 shots.  My group, while nothing to write home about, was still respectable for me - 2" centre to centre for all 5 - using the same patch for each shot.  Spit was the lube of choice. Nowadays, I use windshield wasther fluid with a bit of body soap added to slow evapouration.  My rifles seemt o shoot identically with this as they do with spit, which is excellent, BTW.